Assuming, as Malthus did, that people breed at a rate above replacement whenever they have the means to do so(which turns out not to be true these days in many

Assuming, as Malthus did, that people breed at a rate above replacement whenever they have the means to do so(which turns out not to be true these days in many countries, and may turn out not to be true for the world as a whole soon), population growth will eventually reach a rate at which the world would be a ball of humans expanding faster than the speed of light. It's hard to imagine human ingenuity figuring out a way to make that happen. Exponential growth is a bitch. HN readers should understand this, because it's the same thing that makes exponential time algorithms unreasonably slow, no matte what hardware you throw at them. A century or two of faster than usual technological growth does not falsify Malthus, nor does a hysterical follower like Ehrlich who made predictions that were obviously ludicrous when he made them (he predicted the extinction of marine animal life by 1980 in 1970, which is not justified by anything Malthus wrote). Declining birthrates in the face of prosperity does - if it lasts.